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NAME | SYNOPSIS | DESCRIPTION | RUN MODES | OTHER OPTIONS | EXAMPLE | VERSION | SEE ALSO | COLOPHON |
ocount(1) General Commands Manual ocount(1)
ocount - Event counting tool for Linux
ocount [ options ] [ --system-wide | --process-list <pids> |
--thread-list <tids> | --cpu-list <cpus> | [ command [ args ] ] ]
ocount is an OProfile tool that can be used to count native hardware
events occurring in either a given application, a set of processes or
threads, a subset of active system processors, or the entire system.
The data collected during a counting session is displayed to stdout
by default or, optionally, to a file.
When counting multiple events, the kernel may not be able to count
all events simultaneously and, thus, may need to multiplex the
counting of the events. If this happens, the "Percent time enabled"
column in the ocount output will be less than 100, but counts are
scaled up to a 100% estimated value.
One (and only one) of the following run modes must be specified. If
you run ocount using a run mode other than command [args] , press
Ctrl-c to stop ocount when finished counting (e.g., when the
monitored process ends). If you background ocount (i.e., with '&')
while using one these run modes, you must stop it in a controlled
manner so that the data collection process can be shut down cleanly
and final results can be displayed. Use kill -SIGINT <ocount-PID> for
this purpose.
command [args]
The command is the application for which to count events.
args are the input arguments required by the application. The
command and its arguments must be positioned at the end of the
command line, after all ocount options.
--process-list / -p pids
Use this option to count events for one or more already-
running applications, specified via a comma-separated list (
pids ). Event counts will be collected for all children of the
passed process(es) as well. You must have privileges for the
user ID under which the specified process(es) are running;
e.g., for a non-root user, the user ID of the process(es) is
the same as that used for running ocount. A lack of privileges
will result in the following failure message:
perf_event_open failed with Permission denied
--thread-list / -r tids
Use this option to count events for one or more already-
running threads, specified via a comma-separated list ( tids
). Event counts will not be collected for any children of the
passed thread(s). See the description of --process-list
concerning required privileges.
--system-wide / -s
This option is for counting events for all processes running
on your system. You must have root authority to run ocount in
this mode.
--cpu-list / -C cpus
This option is for counting events on a subset of processors
on your system. You must have root authority to run ocount in
this mode. This is a comma-separated list, where each element
in the list may be either a single processor number or a range
of processor numbers; for example: '-C 2,3,4-11,15'.
--events / -e event1[,event2[,...]]
This option is for passing a comma-separated list of event
specifications for counting. Each event spec is of the form:
name[:unitmask[:kernel[:user]]]
Note: Do not include a count value in the event spec, as that
parameter is only needed when profiling.
You can specify unitmask values using either a numerical value
(hex values must begin with "0x") or a symbolic name (if the
name=<um_name> field is shown in the ophelp output). For some
named unit masks, the hex value is not unique; thus, OProfile
tools enforce specifying such unit masks value by name. If no
unit mask is specified, the default unit mask value for the
event is used.
The kernel and user parts of the event specification are
binary values ('1' or '0') indicating whether or not to count
events in kernel space and user space.
Note: In order to specify the kernel/user bits, you must also
specify a unitmask value, even if the running processor type
does not use unit masks — in which case, use the value '0' to
signify a null unit mask; for example:
-e INST_RETIRED_ANY_P:0:1:0
^ ^ ^
| | |--- '0': do not count user space
events
| |-- '1': count kernel space events
|-- '0': the null unit mask
Event names for certain processor types include a _GRP<n>
suffix. For such cases, the --events option may be specified
with or without the _GRP<n> suffix.
When no event specification is given, the default event for
the running processor type will be used for counting. Use
ophelp to list the available events for your processor type.
--separate-thread / -t
This option can be used in conjunction with either the
--process-list or --thread-list option to display event counts
on a per-thread (per-process) basis. Without this option, all
counts are aggregated.
NOTE: If new threads are started by the process(es) being
monitored after counting begins, the counts for those threads
are aggregated with their parent's counts.
--separate-cpu / -c
This option can be used in conjunction with either the
--system-wide or --cpu-list option to display event counts on
a per-cpu basis. Without this option, all counts are
aggregated.
--time-interval / -i interval_length[:num_intervals]
Note: The interval_length is given in milliseconds. However,
the current implementation only supports 100 ms granularity,
so the given interval_length will be rounded to the nearest
100 ms. Results collected for each time interval are printed
immediately instead of the default of one dump of cumulative
event counts at the end of the run. Counters are reset to
zero at the start of each interval.
If num_intervals is specified, ocount exits after the
specified number of intervals occur.
--brief-format / -b
Use this option to print results in the following brief
format:
[cpu or
thread,]<event_name>[:umask[:K:U]],<count>,<percent_time_enabled>
[ <u32> ,]< string >[< u32>[<bb>]],< u64 >,<
double >
The umask, Kernel and User modes are only printed if the
values were specified as part of the event. The 'K' and 'U'
fields are binary fields separated by colons, where the value
for each binary field may be either '0' or '1'.
If --timer-interval is specified, a separate line formatted as
timestamp,<num_seconds_since_epoch>[.n]
is printed ahead of each dump of event counts. If the time
interval specified is less than one second, the timestamp will
have 1/10 second precision.
--output-file / -f outfile_name
Results are written to outfile_name instead of interactively
to the terminal.
--verbose / -V
Use this option to increase the verbosity of the output.
--version / -v
Show ocount version.
--help / -h
Display brief usage message.
--usage / -u
Display brief usage message.
$ ocount make
This man page is current for oprofile-1.2.0git.
operf(1).
This page is part of the oprofile (a system-wide profiler for Linux)
project. Information about the project can be found at
⟨http://oprofile.sourceforge.net/news/⟩. If you have a bug report for
this manual page, see ⟨http://oprofile.sourceforge.net/bugs/⟩. This
page was obtained from the project's upstream Git repository ⟨git⟩ on
2017-07-05. If you discover any rendering problems in this HTML ver‐
sion of the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original man‐
ual page), send a mail to man-pages@man7.org
oprofile 1.2.0git Wed 05 July 2017 ocount(1)
Pages that refer to this page: oprofile(1)